Process and apparatus for hardening heading-dies



R. LE F. GILMA PROCESSAND APPARATUS FOR HARD APPLICATION F 01 R. LE F.GILMAN. PROCESS AND APPARATUS FOR HARDENING HEADING DIES. 1,334,606.

A LICATION FILED JULY 24, 1919- UNITED STATLEE PATENT OFFICE.

ROY LE FOREST GILMAN, 0F BRIQJTOL, CONNECTICUT.

PROCESS AND .[tIl AItATUEi FOR HARDENING I-IEAlDING-DIES.

menses.

Application filed July 2 t, 15219.

To (all whom it may concern Be it known that I, Roy Ln Former GIL- MAN,a citizen of the United States, residing at Bristol, in the county ofHartford and citate of Connecticut, have invented certain new and usefulimprovements in Processes and Apparatus for I-lardening lleading- Dies,of which the following is a specification.

My invention relates to improvements in processes and apparatus forhardening heading dies, being primarily adapted, as shown and describedbelow, for use with dies for making steel balls for ball bearings, andthe object of my improvement is to provide means for applying the waterthat serves as the cooling medium to the dies in the hardening processso that the hardening will be effected in a superior manner, whereby thelife and efficiency of the dies will be appreciably enhanced.

In the accompanying drawing Figure 1 is a diagrammatic View showing onearrangement of apparatus for carrying out my invention and in which thedie, of circular form, is positioned horizontally and the two conductorsfor effecting the delivery of the cooling water are positioned vertically.

Fig. 2 is an end elevation of the hardening chamber of apparatusarranged with the water tubes horizontal, and in the position to receivethe die.

Fig. 3 is a similar view in position for use, with the water directinghood swung to the upper position.

Fig. 41 is a sectional view on the line 4.4: of'Fig. 2.

5 is a sectional view on the line 55 of Fig. 3. i

Fig. 6 is a plan view, on a reduced scale, oij a battery of hardeningunits, with the parts in different positions.

Fig. 7 is a front elevation of part of the same.

Fig. 8 is an end elevation of the same.

Fig. 9 is a diagrannnatic View of another form of apparatus for using myinvention.

Fig. 10 is a. sectional view showing an application of the principleinvolved in my invention for hardening a special piece of ma terialhaving a relatively deep impression.

The die 10 shown in the drawing as one form of die for which my improvedprocess and apparatus for hardening dies are adapted is of the usualform used as a head- Specification of Letters Patent.

Patented Mar. 23, 1920.

Serial No. 312,927.

ing die in the formation of balls for ball bearings and comprises acylindrical block of appreciable thickness and diameter, has a cup 11 inthe form of a semi-spherical form at each end face, positioned at theends of the axial line, of the form desired for the material to beoperated upon, the die being of the double form, as usual, and the saidcups or depressions 11 are connected by an axially positioned passage12, also as usual.

In the manner of carrying out my process as illustrated by the apparatusshown in Fig. 1 the die 10 is positioned horizontally, the axis beingvertical, so that there is a cup 11 at the middle of the end face 13 atthe top side and also a cup 11 at the middle of the end face 13 at thebottom. The said die 10 is heated to the critical temperature in afurnace of suitable form before being placed in the position forhardening shown in Fig. 1.

After being so heated and positioned as mentioned, being supported inany suitable and proper manner, the hardening is effected by means ofwater, and the manner of applying the said water involves certainspecial features that will be described.

The top and bottom end faces 13 are treated substantially alike and thecooling water is conducted to the said end faces by means of similarconductors 1d of moderate bore that are positioned along the axial lineof the die 10, each terminating with the inner end opposed to andadjacent the cup 11, and separated from the plane of the end face 13 bya iplatively small space 17.

The delivery tubes or conductors 14; are accordingly adapted to deliverthe cooling water so that the portions of the die that will firstreceive and be cooled by the water are the two cups 11, which aredirectly in line with the tubes 14. After the first impact of the wateragainst the cup portion 11 of the end faces 13 the water, which isdelivered under pressure, and may be at a pressure of 120 pounds, willbe diverted and will spread out laterally, radially. In order to guidethe water in the outward lateral flow and to insure substantiallysimilar and equally efficient results for the upper and lower faces 13 Iprovide on the inner end portions of the tubes 14 flat annular platestructures 16 that are spaced from the end faces 13 by a relativelyshallow water space 17, and which structures may be provided on theperipheries each with an inwardly directed flange 18 of suitable lengthto slightly divert the water inwardly toward the medial axial plane. Theoutflow passage or discharge is in the form of the annular open space 19between the opposed edges of the flanges 18.

I find that dies that are hardened in substantially the manner indicatedand de-.

parts of the apparatus corresponding to those shown in Fig. 1 areshifted to correspond, and there are added certain features that will bedescribed.

Thus the delivery tubes 14*. are horizontal and have the water divertingor guiding plate structures 16" mounted on the inner ends thereof. Thusthe water is directed horizontally so as to impinge on the cup portions11 0]": the die 10 and is spread out on all sides of the axis in aradial plane.

As a structural detail, the two plate structures 16 are connectedtogether by a plurality of cross connecting members 20 so as to form acradle structure of suitable form for receiving and supporting the die10 in proper position for being operated upon, and on the inner faces ofthe said plate structures are mounted a plurality of inwardly projectinglug devices 21, opposed to the end faces 13 of the die 10, for providingthe proper space for the Water discharge at the ends of the die. Theupper portion 22 of the cradle structure described is open to pro vide amouth for admitting the die.

As an auxiliary guide for the water discharge I inclose thestructuredescribed in a hood 23 the walls of which are in spaced relation to thesaid structure so as to provide on all sides a passage of ample capacityfor the delivery of the water discharge, the said hood 23 having anoutlet 24 in the side wall that inthe position for use is at the bottomposition so as to deliver the discharge downwardly and away from theapparatus.

Thus in the position for use the outlet 24: of the hood 23 is inregistration with the open space 19 between the opposed flangestructures 18 on the lower edge portions of the end plates 16 and on theupper side there is opposed to the open space 19 between the flangestructures 18 a platelike wall structure 25 that is part of the peripheral Wall of the hood 23.

The flange structures 18 on the lower side are relatively long andextend inwardly ap preciably, so that the open discharge space 19therehetween is relatively reduced, so as to direct the fiow of thecooling or quenching water or other liquid inwardly over the corners ofthe die and this particular form of structure is continued from the saidlower side upwardly on each side equally so that the total extent forthe reduced discharge space is approximately one half of thecircumference.

The flange structures 18 on the upper side are relatively short so thatthe open space 19 is such as to admit the die therethrough. I find,however, that by positioning the exterior plate or outer wall 25 closeto the edges of the end plates lb so as to restrict the space 26therebetween a compensating cficct is produced to compensate for theelt'ect of the relatively wide opening 19 so as to direct the coolingmedium over the corners oi the die 10 efliciently on the upper side ofthe said die 10.

In order to admit the die to the cradle structure the hood 23 is swungso that the outlet 2% is on the upper side and in order that this can bedone the hood 28 is pivot ally mounted on the supply pipes. As shown,the end walls 27 of the hood 23 have holes 28 the walls of which serveas bearings that are journaled on the opposed portion 29 of the pipesl-l. The hood 23 is swung so that the discharge outlet 2% is inregistration with the passa e 19" on the upper side for admitting theoie, and is swung to the operating position. after the (lie is in place.

The device described may be used alone, as a single unit, or a pluralityof such units may be arranged to be manipulated by a single operator,with the different units in different stages of operation, as may be convenient.

In the structure shown in Fig. 5 the end plate 16 is screwed on to thethreaded inner end of the tube 14 and a lock nut 30 serves to positionthese parts, and a spacing tube 31 on the tube 1 1 serves as a spacerfor the end wall 27 of the hood 23 relatively to the end plate 16.

Also, the hood is made up of two matingmain parts 32 that are of propersize and shape to cooperate to form the complete hood structure, andthese are held together by a binding plate 33 at the middle of thestructure that overlaps the opposed edge portions 34: of the said mainparts 32 and are secured thereto by the holdin screws I11 Fig. 6 thereare shown four of the units such as described and which are designatedas a whole by the character .36. The two supply pipes l t" for each unit36 support by a journal connection the hood structure 23 and areconnected in Y-torm to the single branch supply pipe 3'7 theflow inwhich is controlled by the cock 38.

The branch pipes 37 extend rearwardl to the header 39 which serves as amechanical support for the hardening unit in cooperation with the topedge of the front wall 41 of the water tank which receives and supportsthe portion i2 of the branch pipe 37 that is intermediate the cook 38and the junction with the header 39.

The hood 23 in the first unit 36 toward the left is shown in the openposition, the cross pieces 20 that serve as the supports for the diebeing exposed, and, as shown, are three in number.

In the construction described means are provided for the delivery of astream of water or other quenching fluid or liquid dircctly into theimpression in the die, as

shown, and such or similar means may be used for operating upon anyparticular part of any block such as may require maximum hardening.Following upon such deliveryof the cooling medium is the guidance thereof over all or any parts of the die or block as may be desired by meansof a suitable jacket structure.

Thus the dies may be of different forms and shapes and the jacketstructure would be modified to correspond.

Irregular impressions, relatively large impressions, and multipleimpressions or particular areas would in some cases require amodification of the details in the application of my invention, and insome cases a multiple application thereof would be needed to produce thedesired result.

In the battery arrangement shown in Fig, 6 I find it convenient toemploy a handle for turning and positioning the hood 23 and which, asshown, comprises a main part 13 in the form of a straight bar that issecured to the side or end face of the said hood by screws and a secondpart in the form of a laterally, outwardly directed branch 45, both ofwhich parts serve as limiting stops in certain positions of the hood.Thus in the closed and operating position the main part 43 engages withthe upper side of the delivery piping structure, as indicated at 16, andin the open position the lateral branch part bears against theunder sideof the said piping structure, as indicated at 17.

In the apparatus described the die operated upon is of the double form,as mentioned, and in the use thereof the dies ob .tained are superior tothose obtained by any process heretofore in use, and one reason for ithe superior result obtained is the fact that there is avoided theproduction of steam or vapor pockets on or adjacent the surfaces to beoperated upon and the effective sweeping away by the liquid flow of suchsteam or vapor as may be formed. Also, the hardening is positivelycontrolled to correspond to the result desired.

1 I find, however, that in the use of the apparatus described thediminutive passage 12 that extends along the axis of the die andinterconnects the bottoms of the two cups or impressions 11 isessentially inactive so far as any useful result is concerned. Actually,however, I find that the said passage may have an influence on thehardening that is appreciably detrimental that is overcome in anotherform of apparatus Fig. 9 in which the said passage is positively usedfor liquid flow.

Apparatus for operating in this manner is shown. diagrammatically inFig. 9. It will be noted, however, that the die l0 that is shown to beoperated upon has only one face 13, shown as the upper face, that has acup or impression 11, the die being a single die, and this is the formof die to which the said apparatus is adapted to be used. i

The said apparatus comprises the vertical, axially positioned deliverytube 14 on the upper side directed toward the impression 11 the radialor end plate part 16 of the water jacket mounted on the lower end of thetube 14 and opposed to the face 13 of the die, and the flange structure18 extending downwardly from the edges of the plate 16, of cylindricalform, and opposed to the periphery of the die. The flange 18 extendsdownwardly for substantially the full depth of the die and the dischargeis directed downwardly from the an nular water passage 48 between thesaid flange and the die.

It will be noted, however, that besides the passage on the exterior ofthe die for 100 the water there is free passageway for water along theaxial diminutive passage 12 that extends from the bottom of theimpression 11 downwardly through the body portion of the die 10.

I find that a die hardened by the apparatus shown in Fig. 9 and justdescribed and having only a single working die has about double the lifeof a die of the double form and hardened in the manner described above,110 so that the choice of the method and apparatus to be used in aparticular case will be determined by the particular circumstances andconditions existent in each case.

In addition to the increased life men- 115 tioned, which appliesparticularly to the wearing qualities in use, there is the feature ofreduced breakage due to internal hardening strains, which hardeningstrains are reduced in number and intensity by my 120 improved process.

In the application of my improved process shown in Fig. 10 the block 10that has the impression 11 that is to he hardened the tube or conductor14E conducts the 5 quenching liquid into the impression and the guideblock 16 that is mounted on the conductor 1%? serves as the distributer.

The impression 11 is relatively deep and of special form, comprising, asshown, an 130 inner end portion 49 of cylindrical form and merging intothe upper or outer portion 50 of semi-spherical form. The tube 14; projects into the said inner end portion 49 and has the peripheral wall inspaced relation to, the side Wall thereof and the guide block 16- hasthe periphery that is opposed to the outer portion 50 spaced therefrom,the char acter 17 serving to represent the outlet water space betweenthe'combined tube 14: and block 16 for the discharge of the quenchingliquid admitted through the tube 14 I claim as my invention 1. Theprocess of hardening a heading die having an impression on one face forforming material under pressure, comprising delivering a quenchingliquid directly into the said impression and guiding the discharge fromthe said impression laterally outwardly over the surface oi the saidface.

Apparatus for hardening a heading die having an impression on one facefor forming material under pressure, comprising a tube for deliveringquenching liquid directly into the said impression and a guide deviceoperatively mounted on the said tube for being opposed to the said facefor guiding the said liquid outwardly laterally over the said face andaway from the said impression.

3. The process of hardening a heading die having two opposite faces eachof which is provided With an impression for forming material underpressure, comprising delivering a quenching liquid sin'iultaneouslydirectly into both of the said impressions.

ROY LE FOREST GILMAN.

